1. Field of the Invention
The present invention relates generally to enclosing generally disc-shaped objects in a box for safe storage. More specifically, the invention relates to both a lens box blank and a lens box erected from the lens box blank, the lens box being suitable for enclosing an optical lens blank, particularly an ophthalmic lens blank, with the lens blank being secured by the box structure to prevent both horizontal and vertical movement of the lens blank in the box during transportation, and to prevent trauma to the lens blank during light impact.
2. Background of the Art
Lens blanks are used as the starting material for corrective lenses in eyeglasses. These xe2x80x9cgenericxe2x80x9d lens blanks are manufactured in bulk quantity by lens manufacturers with or without any particular refractive correction. The lenses basically have a convex top, concave bottom and cylindrical side wall. The side wall is eventually cut or ground to the proper fit within an ophthalmic lens frame. The correction is prepared by molding into the lens blank or by a combination of lens elements to form the appropriate prescription from a prescribing optician. Thus, the lens manufacturer is able to form or manufacture generic lens blanks in large production quantities. When a patient is treated, and corrective lenses are prescribed by an optometrist or other professional, an optician may be employed to select the proper lens or combine the proper lens blanks. To prevent an optician from having to maintain a very large supply of lenses all tailored to different prescriptions, lens blanks may be utilized. In that case, an optician would then select a generic lens blank and grind it to the required correction or frame fit. With the large number of lenses being prescribed, there is a large number of lens blanks being shipped from the manufactures to optical shops across the country.
The xe2x80x9cgenericxe2x80x9d lens blanks have a convex top surface, a concave bottom and a generally cylindrical side wall. The lens blanks are usually designed and manufactured so that the convex top may remain in tact, the grinding occurring only on the bottom surface (and sides for frame fit). Thus it is important that the convex top surface remain free of any scratches or other imperfections as it will not be subsequently abraded or smoothed. Therefore, an important consideration in designing an enclosure box for transportation of such lens blanks is that contact between the convex top surface of the lens blank and the shipping container must be minimized during shipment. The shipping container should also be sufficiently sturdy that if accidental impact occurs during transportation, the box will absorb the impact without exposing the ophthalmic lens blank to contact with an abrading surface. The lens blank must be retained within the shipping enclosure such that vertical movement of the lens blank within the enclosure is minimized. One additional benefit of restricting movement on the lens blank is elimination of the annoying xe2x80x9crattlingxe2x80x9d that accompanies random movement of an unsecured object within a box.
Numerous examples exist of containers adapted to transport lenses and the like. One example of such prior art is Seger, U.S. Pat. No. 3,122,298, which discloses a container having slightly inclined sidewalls, handles, and a removable top. In the Seger enclosure, the inclination of the side walls is outwardly from the base upward. Thus, the Seger enclosure would not be operative to prevent vertical movement of the lens blank.
Another prior art example of a container is Buttery, U.S. Pat. No. 2,372,312, which discloses a folding octagon paper box having a general folding pattern and configuration for assembly of an octagonal container. Buttery does not have inclined sidewalls and thus would not be adapted to restrict vertical movement of the lens blank.
Towell, U.S. Pat. Nos. 1,968,660 and 1,968,661, show open topped display containers for candy and other confectionery having outwardly inclined side walls and no top to enclose the container.
Yet other prior art includes the use of styrofoam half sections to enclose lens blanks which are then manually inserted into a box enclosure for shipment.
U.S. Pat. No. 5,454,469 describes a lens box for safe storage and transportation of an optical lens blank having convex top and concave bottom surfaces and a cylindrical side wall, the junction of said top and bottom surfaces with said side wall defining a top ridge and a bottom ridge, comprising:
vertically spaced apart, substantially parallel top panel and bottom panel;
horizontally spaced apart, substantially parallel first and second side walls, said side walls being generally perpendicularly connected to said top and bottom panels;
a plurality of gussets, each of said gussets being connected to said top and bottom panels thereby defining an interior generally enclosed space between said top and bottom panels, said side walls and said gussets, each gusset and said top panel further defining an interior angle and an exterior angle, and each gusset and said bottom panel further defining an interior angle and an exterior angle and wherein said interior angle between each gusset and said top panel is greater than said interior angle between that same gusset and said bottom panel such that said gussets are inclined upwardly and inwardly from said bottom panel such that upon insertion of a said lens blank into said lens box, said gussets tangentially contact said lens blank top ridge at a point corresponding to the intersection of said lens blank side wall and said gussets thereby securing said lens blank against any substantial horizontal and vertical movement in said box.
The invention encompasses both a T-square lens box blank that can be folded and secured to form a lens box and the lens box formed from the lens box blank. The cross-bar of the T-square lens box blank has slidable/adjustable lens supporting frames on both sides of the cross-bar. The rear stem of the T-square lens box blank provides the top of the lens box structure and both the front and rear of the lens box. The resultant lens box places little contact surface area of the internal box support against the front lens surface, with the majority of the lens support being provided by contact of the lens box with the edges of the lens, not the viewing surface of the lens.